Abstract.Pleistocene
chronostratigraphy in Estonia is based on 60 radiocarbon (14C, 14C
AMS), 63 TL/OSL, and 17 10Be datings from 57 studied
sites/sections that cover a time span from approximately
200 000 yr BP to the Pleistocene–Holocene chronostratigraphic
boundary. For the first time all scattered data from 40 years of
chronological study into Estonian Pleistocene are presented together and
critically analysed in regard to validity of obtained ages. Half of the
relatively abundant but scattered chronological data cover only the youngest
5000–6000 year part of the Late Weichselian. New OSL datings, together
with the results of earlier palynological, carpological, and diatom studies,
have invalidated almost one-third of the available 14C dates,
obtained mostly in the late 1960s and 1970s. Thermoluminescence ages from
tills, available from the early 1980s, are very inconsistent within the studied
sections and are considered to be unreliable because of questionable bleaching
of the TL signal. The results
of the 10Be method, recently applied to the study of deglaciation
chronology of the Estonian territory, do not contradict the earlier age
estimations. However, due to relatively large uncertainties of the method, the
results were not able to refine the existing Late-Glacial chronology in Estonia.

Abstract. Eskers are frequent landforms in the
palaeo-glacial erosional zone. A channelized network of
subglacial water conduits above the nonpermeable surface is an obligatory
precondition for esker genesis. The current
study supports the results of the investigations of modern high-arctic esker
formation. The structure and stratification of the esker deposits indicate fast
changes and alternation of erosion–transport–accumulation processes. The extent
of esker systems over tens or hundreds of kilometres indicates their
time-transgressive inherited genesis.

The
territory of Estonia lies in the periphery of the esker distribution area of
the Scandinavian glaciation. Radial eskers in
Estonia consist mainly of coarse-grained deposits of local Palaeozoic
bedrock. The combination of eskers and glaciokarst kettle holes or
glaciofluvial plateaus and kame fields is
frequent. The ridge-like glaciofluvial topography, morphologically similar to
eskers but formed in stagnant ice is specified as crevasse fillings, and
is genetically related to kames.

Grain
size of the bottom sediments of Lake Väike Juusa (southern Estonia) as the
indicator of water-level fluctuations; 40–51

Jaan-Mati Punning, Jaanus Terasmaa, and Ene Kadastik

Abstract. Surface
sediments and sediment cores from Lake Väike Juusa were studied in order to examine the dependence of the sedimentation regime on the topography
and development of the lake. Close relationship was established between the
grain size of the surface samples and depth of water at the sampling site. The
data obtained show that in the lake the accumulation area is situated deeper
than 4.0 m. The grain size data for three sediment cores allowed
reconstruction of lake-level fluctuations and
their amplitude.

Abstract.The pollen diagram with accelerator
mass spectrometer (AMS) radiocarbon dates covering
Holocene sediments from the Otepää Heights gives a general overview of the
vegetation history of the area. The pollen assemblage zones (PAZs) defined on
the pollen diagram of the Lake Väike Juusa
core in general correspond to the PAZs on the stratigraphic chart of Holocenesediments in Estonia. Comparison of the
pollen profile of Lake Väike Juusa with other pollen diagrams from the same area enables us to distinguish
differences in the vegetation history induced by local factors. The most
characteristic differences occur in the Picea pollen content. Picea migrated
to the Otepää Heights in small patches
already at the end of the Boreal Chronozone and started to spread at the end of
the Atlantic Chronozone. This is about 1000 years earlier than shown in the Holocene stratigraphic chart of Estonia. Also
human activity and forest fires in the areas surrounding the study sites
have affected the vegetation dynamics on a local scale during the last two
millennia.